'Panicky' Bayern held in Freiburg to boost Leverkusen title hopes
Mathys Tel's 35th-minute stunner had cancelled out an impressive opener from Freiburg captain Christian Guenter, before Jamal Musiala's spectacular solo effort looked to have snared the three points for Bayern.
Hoeler however had other ideas, chipping a volley through a crowded Bayern penalty area and past a helpless Manuel Neuer.
Bayern manager Thomas Tuchel criticised his players' "body language and lack of bite" in the first half an hour, telling DAZN "we played completely without structure and had no discipline and weren't in our positions."
Calling his side "panicky", Tuchel said: "We did things that we've never trained, that we've never spoken about.
"We played like it was the 85th minute and we were a goal down."
Musiala told DAZN he felt "frustrated".
"Since I've been at Bayern it's been in my head that we must win and we hate to lose. We want to win the Bundesliga, we want to win titles," he said.
Bayern have now failed to win away from home in four matches dating back to January in both the Bundesliga and Champions League.
Tuchel's side face Lazio at home in the last 16 of the Champions League on Tuesday, staring down an early exit with a 1-0 deficit from the first leg in Rome.
'Simply instinct'
Xabi Alonso's unbeaten Bayer Leverkusen can go 10 points clear of the Bavarians with a win against lowly Cologne in their derby clash on Sunday as they chase a first-ever Bundesliga title.
"We played a good game" Freiburg's Vincenzo Grifo told DAZN. "It's clear that you have to suffer against Bayern."
Guenter blasted the hosts into the lead after 12 minutes, unleashing a spinning rocket from outside the box and into the bottom right of the goal.
The goal was the Freiburg captain's first of the season and the club's only strike from outside the box this campaign.
Not content to allow Guenter to dominate the highlights reel, Tel hit back with a dream goal of his own, curling in a long-range effort on his second league start this season.
With 15 minutes remaining, and Bayern dominating possession but failing to carve out clear chances, Musiala dribbled past three Freiburg defenders and blasted a low shot into the right corner.
"Simply instinct" said Musiala of the goal. "You try and you dribble and see what you can create."
Despite holding the lead Bayern grew passive, dropping deep to hold onto their slender lead.
With just three minutes of regular time remaining, Hoeler held off several Bayern defenders and chipped a volley over Neuer and into the goal.
The draw spoilt the first day at work for Bayern sporting director Max Eberl, who said during his unveiling this week the side would still push Leverkusen for the title.
The point sees Freiburg finish the night in ninth place in a crowded Bundesliga table, with only five points separating seventh and 15th places.